SMTP Troubleshooting

Simple Mail Transfer Protocol

  • Is the server running?
    • ps aux | grep exim
    • sudo service exim4 status
    • sudo service exim4 start
  • Is the server listening on public ip?
    • netstat -atu | grep smtp
  • Are there errors in log files?
    • Check /var/log/exim4 directory

Simple Mail Transfer Protocol Debugging

  • Send/Receive messages from/to many different accounts.
  • Use dig to check if DNS is correct
    • dig @ns1.thegummibear.com thegummibear.com MX

not getting correct reply-to address

  • Make sure that /etc/hosts has the fqdn of your mailserver in it. Also, make sure that the same line has a reference to whatever you put in /etc/hostname. Mine looks like this:

      144.38.199.52 	mail.thegummibear.com mail-thegummibear
    

Because my hostname (in /etc/hostname) was mail-thegummibear